Existing printed steel sheets have been produced by a silk screen method, a roll printing method, or a laminating method. However, it is impossible to print a high resolution pattern using such a conventional printing method. In addition, the conventional printing method has disadvantages of an increase in the production cost due to production of a screen or a roll, of a low error rate, and of an impossibility to produce products of various colors. To solve an issue of the conventional printing method, an attempt has been made to apply a conventional inkjet printing method to steel to compensate for disadvantages of an existing printed steel sheet manufacturing method.
However, since when ink is jetted directly onto a steel material, it is difficult to ensure adhesion between the ink and the steel material due to an absence of an absorption layer, utilization as a product is impossible. In addition, when conventional ink is applied to a steel material by inkjet jetting, all processability, solvent resistance, and the like, as well as adhesion need to be satisfied. Thus, there is a limitation to replacement of an existing printed steel sheet.